|Jung, Hans Joachim|
|Phillips, Ronald -|
Submitted to: Cell Wall Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2010
Publication Date: July 25, 2010
Citation: Jung, H.G., Phillips, R.L., Mertens, D.R. 2010. The sfe Maize Mutant: Reduced Ferulate Cross Linking Improves Rumen Cell Wall Degradability and Milk Production by Dairy Cows [abstract]. XII Cell Wall Meeting, July 25-30, 2010, Porto, Portugal. p. 60. Technical Abstract: A putative mutant has been identified in maize that reduces ferulate cross linking of lignin to arabinoxylan in mature stover, increases in vitro rumen cell wall degradability, and increases milk production by cows. The seedling ferulate ester (sfe) mutant was discovered in a Mu transposon-mutated population of the maize inbred W23. The original mutant plant had a 50% reduction in ferulate ester concentration in the first true leaf at the three-leaf stage. Four near-isogenic lines of the W23sfe mutant were compared to W23 in replicated field trials. Ferulate ester concentration in seedlings leaves of W23sfe lines were only 9% lower than W23; however, at silage maturity the stover had reductions in ferulate ethers cross links of -15, -13, and -30% for leaf blades, sheaths, and stems, respectively. Total cell wall, lignin, xylose, and arabinose concentrations were all slightly lower in W23sfe stover. The molar ratios of total ferulates (esters and ethers)-to-arabinose and arabinose-to-xylose did not differ between W23 and W23sfe lines, suggesting that biosynthesis of the entire feruloylarabinoxylan complex was down-regulated by the sfe mutation. When exposed to rumen bacteria in vitro, 24-h cell wall polysaccharide degradability was increased 7, 8, and 4% for leaf blade, sheath, and stem, respectively, of W23sfe compared to W23. When silage from two of the W23sfe lines were fed to dairy cows as part of mixed forage and grain diets, feed intake and milk production were increased 6 and 4%, respectively, relative to W23. The cows were also less selective in eating behavior against cell wall material when fed W23sfe-containing diets. We believe this is the first report of a targeted modification in ferulate-mediated cross linking in a grass and a subsequent improvement in animal feeding value.